TDS is the total mass of dissolved inorganic salts and organic matter in water, expressed in mg/L (= ppm). Seawater is ~35,000 ppm TDS; brackish water 1,000–15,000 ppm; potable water <500 ppm. TDS is measured directly by evaporating a known volume and weighing the residue, or estimated from electrical conductivity (a TDS-to-EC factor of 0.55–0.70 is typical for natural waters). TDS sets the basic RO design envelope: feed TDS picks membrane class (SWRO vs BWRO), determines pump pressure, and drives the salt-rejection specification needed to hit potable permeate. WHO recommends <600 ppm TDS for palatability; up to 1,000 ppm is acceptable. There is no strict health-based TDS limit. Salinity narrowly refers to dissolved salt content (mostly NaCl + sulfate + bicarbonate). TDS includes salts plus dissolved organics, silica, and trace metals. Yes, but understand the meter computes TDS from conductivity using a fixed factor. For accurate values on unusual waters, gravimetric TDS in a lab is required. ForeverPure has supplied desalination, high-pressure pumps, and energy-recovery devices to commercial and industrial customers since 2003. Contact our engineers for sizing, quotes, or technical support.TDS (Total Dissolved Solids) (TDS)
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What's the WHO TDS limit for drinking water?
How is TDS different from salinity?
Can I just use a handheld TDS meter?
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